A multinational survey of companion animal veterinary clinicians: How can antimicrobial stewardship guidelines be optimised for the target stakeholder?

Antimicrobial stewardship initiatives are widely regarded as a cornerstone for ameliorating the global health impact of antimicrobial resistance. Within companion animal health, such efforts have largely focused on development and dissemination of antimicrobial stewardship guidelines (ASGs). However, there have been few attempts to understand veterinarian attitudes towards and knowledge of ASGs or to determine how awareness regarding ASGs might best be increased. An online survey regarding ASGs was formulated for veterinarians who treat companion animals. The survey was distributed across 46 European and associated countries between 12 January and 30 June, 2022. In total, 2271 surveys were completed, with 64.9% of respondents (n = 1474) reporting awareness and usage of at least one ASG. Respondents from countries with greater awareness of ASGs tended to report more appropriate use of antimicrobials (Spearman's rank coefficient = 0.6084, P ≤ 0.001), with respondents from countries with country-specific ASGs tending to score highest across both awareness and appropriate use domains. Respondents prioritised guidance around antimicrobial choice (82.0%, n = 1863), duration of treatment (66.0%, n = 1499), and dosage (51.9%, n = 1179) for inclusion in future ASGs, with 78.0% (n = 1776) of respondents preferring ASGs to be integrated into their patient management system. Awareness of ASGs and their use in companion animal veterinary practice appears to be greater than previously reported, with respondents tending to report antimicrobial prescription decision making broadly in line with current clinical recommendations. However, further initiatives aimed at maximising accessibility to ASGs both within countries and individual veterinary practices are recommended.

Varlitinib plus capecitabine in second-line advanced biliary tract cancer: a randomized, phase II study (TreeTopp)

Background

Patients with advanced biliary tract cancer who progress on first-line therapy have limited treatment options. The TreeTopp study assessed varlitinib, a reversible small molecule pan-human epidermal growth factor receptor inhibitor, plus capecitabine in previously treated advanced biliary tract cancer.

Patients and methods

This global, double-blind, randomized, placebo-controlled phase II study enrolled patients with confirmed unresectable or metastatic biliary tract cancer and disease progression after one prior line of gemcitabine-containing chemotherapy. Patients received oral varlitinib 300 mg or placebo twice daily (b.i.d.) for 21 days, plus oral capecitabine 1000 mg/m² b.i.d. on days 1-14, in 21-day treatment cycles. Co-primary endpoints were objective response rate and progression-free survival (PFS) according to RECIST v1.1 by Independent Central Review.

Results

In total, 127 patients received varlitinib plus capecitabine (n = 64) or placebo plus capecitabine (n = 63). The objective response rate was 9.4% with varlitinib plus capecitabine versus 4.8% with capecitabine alone (odds ratio 2.28; P = 0.42). Median PFS was 2.83 versus 2.79 months [hazard ratio (HR), 0.90; 95% confidence interval (CI), 0.60-1.37; P = 0.63] and overall survival was 7.8 versus 7.5 months (HR, 1.11; 95% CI, 0.69-1.79; P = 0.66), respectively. In a subgroup analysis, the addition of varlitinib appeared to provide a PFS benefit in female patients (median, 4.1 versus 2.8 months; HR, 0.59; 95% CI, 0.28-1.23) and those with gallbladder cancer (median, 2.9 versus 1.6 months; HR, 0.55; 95% CI, 0.26-1.19). Grade ≥3 treatment-emergent adverse events were reported in 65.6% of patients receiving varlitinib plus capecitabine versus 58.7% of those receiving capecitabine alone.

Conclusions

In patients with advanced biliary tract cancer, second-line treatment with varlitinib plus capecitabine was well tolerated but did not improve efficacy versus capecitabine alone. A PFS benefit was suggested in female patients and those with gallbladder cancer.

•

In advanced biliary tract cancer, second-line varlitinib plus capecitabine did not improve efficacy versus capecitabine alone.

•

Varlitinib was well tolerated in combination with capecitabine.

•

Subgroup analyses suggested varlitinib plus capecitabine may benefit female patients and those with gallbladder cancer.

P946Abnormal ankle brachial indices are associated with ischemic stroke: evidence from a large cohort study

Background

Peripheral arterial disease is a marker of aggressive atherosclerosis. The ankle brachial index (ABI) is a simple and non-invasive tool to diagnose peripheral arterial disease (PAD). Patients with PAD are at increased risk for ischemic strokes and other cardiovascular diseases.

Purpose

To evaluate the association of abnormal ABI and poorly compressible vessels with ischemic stroke in a large patient cohort.

Methods

We analyzed lower extremity vascular studies of all patients with ABI measurements at a tertiary care hospital between January 1996 and August 2018. PAD is defined as ABI<1.0, and poorly or non-compressible (PC/NC) arteries as ABI>1.4 while ABI between 1.0–1.4 is normal. Association of these ABIs with new ischemic stroke events post ABI measurement were analyzed after adjusting for high risk confounders such as atrial fibrillation. Hazard ratios (HR) were calculated using multivariable Cox proportional regression with 95% confidence intervals.

Results

In total, 38,016 unique patients (mean age 66.1±14.8 years, female 42.3%) were included. Abnormal ABI was found to be more prevalent among elderly male patients compared to patients with normal ABI. In contrast to non-PAD patients, both PAD and PC/NC patients as defined by ABI had a statistically significant risk of ischemic stroke, with PAD conferring the greatest risk compared to PC/NC vessels. The data is summarized in Table 1.

Table 1 Unadjusted HR p-value Adjusted HR p-value PAD vs. No PAD 2.77 (2.62, 2.92) <0.001 2.10 (1.98, 2.22) <0.001 PC/NC vs. No PAD 2.11 (1.95, 2.28) <0.001 1.38 (1.26, 1.51) <0.001 PAD vs. PC/NC 1.37 (1.28, 1.46) <0.001 1.37 (1.28, 1.48) <0.001 Adjusted and unadjusted hazard ratios with p-values. HR adjusted for age, sex, atrial fibrillation, ischemic stroke, transient ischemic attack, chronic heart failure, diabetes mellitus, hyperlipidemia, hypertension, and coronary artery disease. PAD = Peripheral artery disease and PC/NC = poorly compressible/non-compressible.

Conclusion

This study adds to the growing body of evidence that PAD and poorly-compressible vessels are independently associated with an increased risk of ischemic stroke. Given the associated risk of cerebrovascular disease, clinicians should aggressively treat to minimize risk factors in those with abnormal ABIs.

P945Abnormalities in ankle-brachial indices are independently associated with new-onset atrial fibrillation

Introduction

Lower extremity physiologic studies are an important non-invasive diagnostic tool in peripheral arterial disease (PAD). PAD and atrial fibrillation (AF) are associated with increased cardiovascular and all-cause mortality.

Purpose

To evaluate the association between PAD and new-onset AF and the risk of stroke.

Methods

We performed a study of all patients without AF undergoing ankle-brachial index (ABI) for any indication between January 1996 to June 2018. The ABI cut-off were as follows: abnormal ABI (0–0.99), normal ABI (1.00–1.39) and poor vessel compressibility (PC) (1.40+). Demographic, comorbidity, and outcome variables were extracted using the electronic medical record.

Results

Overall, 34,441 patients (mean age 66.8±14.3, 57.3% male, 88.2% white) were included in the study with a median follow-up of 7.2 years (interquartile range, 3.0–12.9 years). Multivariate Cox proportional hazard analysis showed increased risk of new-onset AF for male sex, older age, hypertension, coronary artery disease, cerebrovascular disease, chronic kidney disease stage III or greater, congestive heart failure, chronic obstructive pulmonary disease, and cancer (all p<0.0001). After adjustment, ABI results were significantly associated with new-onset AF, particularly poorly-compressible vessels (adjusted HR: 1.42 (1.30–1.55), p<0.0001) compared to abnormal ABI (adjusted HR: 1.12 (1.05–1.20), p=0.0012). Patients with atrial fibrillation were more likely to experience ischemic stroke (39.2% versus 16.1%, p<0.0001).

Conclusion

Abnormalities in ABI results, particularly poorly-compressible vessels, are independently associated with new-onset atrial fibrillation in a large ambulatory cohort. While the mechanism cannot be assessed, common inflammatory mechanisms and increased vascular stiffness may play an important role. Identification of AF in these at-risk patients may improve cardiovascular outcomes.

Spatial variation in the parasite communities and genomic structure of urban rats in New York City

Brown rats (Rattus norvegicus) are a globally distributed pest. Urban habitats can support large infestations of rats, posing a potential risk to public health from the parasites and pathogens they carry. Despite the potential influence of rodent-borne zoonotic diseases on human health, it is unclear how urban habitats affect the structure and transmission dynamics of ectoparasite and microbial communities (all referred to as "parasites" hereafter) among rat colonies. In this study, we use ecological data on parasites and genomic sequencing of their rat hosts to examine associations between spatial proximity, genetic relatedness and the parasite communities associated with 133 rats at five sites in sections of New York City with persistent rat infestations. We build on previous work showing that rats in New York carry a wide variety of parasites and report that these communities differ significantly among sites, even across small geographical distances. Ectoparasite community similarity was positively associated with geographical proximity; however, there was no general association between distance and microbial communities of rats. Sites with greater overall parasite diversity also had rats with greater infection levels and parasite species richness. Parasite community similarity among sites was not linked to genetic relatedness of rats, suggesting that these communities are not associated with genetic similarity among host individuals or host dispersal among sites. Discriminant analysis identified site-specific associations of several parasite species, suggesting that the presence of some species within parasite communities may allow researchers to determine the sites of origin for newly sampled rats. The results of our study help clarify the roles that colony structure and geographical proximity play in determining the ecology of R. norvegicus as a significant urban reservoir of zoonotic diseases. Our study also highlights the spatial variation present in urban rat parasite communities, indicating that rats across New York City are not reservoirs for a homogenous set of parasites and pathogens. As a result, the epidemiological risks may be similarly heterogeneous for people in urban habitats.

Cytomegalovirus infection is associated with an increase in systolic blood pressure in older individuals

BACKGROUND

Cytomegalovirus (CMV) is a chronic infection that is widely distributed in the population. CMV infects a range of tissues, including endothelium, and viral replication is suppressed by the host immune system. Infection is associated with increased risk of mortality from vascular disease in older people, but the mechanisms behind this have not been determined.

AIM

We investigated the association between CMV infection and cardiovascular phenotype in a cohort of healthy elderly donors.

DESIGN

CMV serostatus and cardiovascular parameters were determined in the Lothian Birth cohort, which comprises 1091 individuals aged 70 years in whom many environmental, biochemical and radiological correlates of vascular function have been determined.

METHODS

CMV serostatus was determined by enzyme-linked immunosorbant assay and correlated with a range of biochemical and phenotypic measures.

RESULTS

Sixty-five percent of participants were CMV seropositive, which indicates chronic infection. The mean sitting systolic blood pressure (SBP) was 149.2 mmHg in CMV seropositive individuals compared with 146.2 mmHg in CMV seronegative subjects (SD 18.7 vs. 19.7; P < 0.017). This association between CMV infection and SBP was not attenuated after adjustment for a wide range of biological and socio-economic factors.

CONCLUSIONS

These data show that CMV infection is associated with an increase in SBP in individuals at age 70 years. The magnitude is comparable to environmental variables such as obesity, diabetes or high salt intake. This is the first evidence to show that a chronic infection may be an important determinant of blood pressure and could have significant implications for the future management of hypertension.

Preliminary Survey of Ectoparasites and Associated Pathogens from Norway Rats in New York City

The Norway rat (Rattus norvegicus) is a reservoir of many zoonotic pathogens and lives in close proximity to humans in urban environments. Human infection with rodent-borne disease occurs either directly through contact with a rat or its excreta, or indirectly via arthropod vectors such as fleas and ticks. Here, we report on the diversity and abundance of ectoparasitic arthropod species and associated pathogenic bacteria from 133 Norway rats trapped over a 10-mo period in Manhattan, New York, NY. Norway rats were host to the tropical rat mite [Ornithonyssus bacoti (Hirst)], the spiny rat mite (Laelaps echidnina Berlese), Laelaps nuttalli Hirst, the spined rat louse [Polyplax spinulosa (Burmeister)], and the Oriental rat flea [(Xenopsylla cheopis) (Rothschild)], with an average of 1.7 species per individual. A flea index of 4.1 X. cheopis was determined, whereas previous studies in New York City reported 0.22 fleas per rat. Multiple species of pathogenic Bartonella were identified from Oriental rat fleas that were related to Bartonella tribocorum, Bartonella rochalimae, and Bartonella elizabethae. However, no evidence of Yersinia pestis or Rickettsia spp. infection was detected in fleas. The identification of multiple medically important ectoparasite species in New York City underscores the need for future efforts to fully characterize the diversity and distribution of ectoparasites on Norway rats, and assess the risk to humans of vector-borne disease transmission.

Novel one-stop multidisciplinary follow-up clinic significantly improves cancer risk management in BRCA1/2 carriers

The purpose of this study is to measure the impact of a multidisciplinary one-stop follow-up clinic (MDOSC) on breast and ovarian surveillance, risk reducing surgery and enrolment in clinical trials in BRCA1/2 carriers. All BRCA1/2 carriers in our region were invited and chose which specialists to see in our MDOSC offering best practice using clinical protocols based on national guidelines and published data. Uptake was evaluated over 24 months recording numbers of individuals undergoing breast and ovarian surveillance, risk reducing surgery, newly diagnosed cancers, their method of detection and participation in clinical trials. 172 (60%) of invited BRCA1/2 carriers chose to attend the MDOSC. Breast surveillance was initiated in 88% and screening frequency altered in 14% of women to comply with national guidelines. Risk reducing salpingo-oophorectomy was chosen by 47% of women and an additional 39% were considering it. The rate of failure to remove fallopian tubes fell from 15 to 3% of procedures (P < 0.01) and peritoneal washings and serial sectioning of tubes and ovaries rose from 25% and 14% before, to 67% (P < 0.001) and 63% (P < 0.001) procedures, respectively, after initiation of our MDOSC. 24% of women considered and 18% decided to undergo risk reducing mastectomy during the follow-up period. Participation in clinical trials increased significantly from 51 to 229 enrolments (P < 0.001). Our novel MDOSC designed to devise an individually tailored cancer risk management strategy had a high uptake amongst our BRCA1/2 carriers. Attendance resulted in improved breast and ovarian cancer risk management.